Bistable mechanism for collapsing and elevating a keyboard in a portable computer

Abstract

A notebook computer is provided with a collapsible keyboard in which a dome sheet with elastomeric key return dome members thereon is horizontally shiftable through elevation and retraction strokes to respectively shift the keys between elevated operating positions in which the domes underlie and support the keys, and retracted positions in which the domes are shifted away from their key-underlying positions. A linkage member interconnected between the computer lid and a drive bar on the dome sheet creates initial triggering movements of the dome sheet through its elevation and retraction strokes in response to opening and closing of the lid. In response to these lid-created triggering movements of the dome sheet, a bistable spring structure connected to the drive bar takes control of the dome sheet and drives it through the balance of the stroke and then releasably retains the fully shifted dome sheet in the resulting stroke end position thereof.

What is claimed is: 
     
       1. Collapsible keyboard apparatus comprising: a plurality of keys supported for movement between elevated and retracted positions;   a first structure operative to (1) shift said keys from said retracted positions to said elevated positions and (2) permit said keys to move from said elevated positions to said retracted positions in response to movement of said first structure respectively through (1) an elevation stroke and (2) a retraction stroke; and   a second structure connected to said first structure and operative in response to a triggering movement of said first structure through an initial portion of either of said elevation and retraction strokes to (1) drive said first structure through the balance of the stroke, and then (2) releasably retain said first structure in the resulting stroke end position thereof.   
     
     
       2. The collapsible keyboard apparatus of claim 1 wherein said collapsible keyboard apparatus is a portable computer keyboard. 
     
     
       3. The collapsible keyboard apparatus of claim 2 wherein said portable computer keyboard is a notebook computer keyboard. 
     
     
       4. The collapsible keyboard apparatus of claim 1 wherein said elevation and retraction strokes are oppositely directed strokes. 
     
     
       5. The collapsible keyboard apparatus of claim 1 wherein said first structure includes a base member having disposed thereon a spaced series of resilient key return members operative to underlie and support said keys in said elevated positions thereof in response to movement of said first structure through said elevation stroke, and to permit said keys to move to said retracted positions in response to movement of said first structure through said retraction stroke. 
     
     
       6. The collapsible keyboard apparatus of claim 5 wherein said base member is a dome sheet and said resilient key return members are elastomeric key return dome members. 
     
     
       7. The collapsible keyboard apparatus of claim 6 further comprising a slide bar member secured to said dome sheet and being movable in opposite directions to move said dome sheet through said elevation and retraction strokes. 
     
     
       8. The collapsible keyboard apparatus of claim 1 wherein said second structure is a bistable spring structure. 
     
     
       9. The collapsible keyboard apparatus of claim 8 wherein said bistable spring structure includes a body portion supported for rotation relative to said first structure and drivingly connected thereto, and spring means for engaging said body portion in a manner permitting said body portion to rotate between two stable positions through an intermediate unstable position. 
     
     
       10. The collapsible keyboard apparatus of claim 9 wherein: said first structure has a slot therein,   said body portion has a drive pin received in said slot, and   said spring means exert generally oppositely directed forces on said body portion in directions generally transverse to its rotational axis.   
     
     
       11. The collapsible keyboard apparatus of claim 8 wherein: said first structure has spaced pairs of oppositely ramped drive surfaces, and   said bistable spring structure includes a pair of spring members supported adjacent said spaced pairs of oppositely ramped drive surfaces and having generally V-shaped end portions resiliently engaging said drive surfaces.   
     
     
       12. The collapsible keyboard apparatus of claim 8 wherein: said first structure has spaced pairs of oppositely ramped drive surfaces, and   said bistable spring structure includes a generally U-shaped spring member having generally V-shaped free end portions resiliently engaging said drive surfaces.   
     
     
       13. The collapsible keyboard apparatus of claim 8 wherein: said first structure has spaced pairs of oppositely ramped drive surfaces, and said bistable spring structure includes a generally rectangular spring member having opposite side portions with generally V-shaped protrusions formed thereon and resiliently engaging said drive surfaces.   
     
     
       14. The collapsible keyboard apparatus of claim 13 wherein said protrusions are inwardly directed protrusions. 
     
     
       15. The collapsible keyboard apparatus of claim 13 wherein said protrusions are outwardly directed protrusions. 
     
     
       16. The collapsible keyboard apparatus of claim 8 wherein said bistable spring structure includes a pair of telescoped, axially spring-biased tie rod assemblies each having a first end pivotally connected to said first structure, and a second end pivotally supported external to said first structure. 
     
     
       17. An electronic device comprising: a housing;   a lid mounted on said housing for pivotal movement relative thereto between open and closed positions; and   a collapsible keyboard carried by said housing and including:   a plurality of keys supported for movement between elevated and retracted positions;   a first structure operative to (1) shift said keys from said retracted positions to said elevated positions and (2) permit said keys to move from said elevated positions to said retracted positions in response to movement of said first structure respectively through (1) an elevation stroke and (2) a retraction stroke; and   a second structure connected to said first structure and operative in response to a triggering movement of said first structure through an initial portion of either of said elevation and retraction strokes to (1) drive said first structure through the balance of the stroke, and then (2) releasably retain said first structure in the resulting stroke end position thereof.   
     
     
       18. The electronic device of claim 17 wherein said electronic device is a portable computer. 
     
     
       19. The electronic device of claim 18 wherein said portable computer is a notebook computer. 
     
     
       20. The electronic device of claim 17 wherein said elevation and retraction strokes are oppositely directed strokes. 
     
     
       21. The electronic device of claim 20 wherein said second structure is a bistable spring structure. 
     
     
       22. A portable computer comprising: a base housing;   a lid portion secured to said base housing for pivotal movement relative thereto between open and closed positions;   a collapsible keyboard carried by said base housing and including: a plurality of keys supported for movement between elevated and retracted positions, and   shifting means operative to (1) shift said keys from said retracted positions to said elevated positions and (2) permit said keys to move from said elevated positions to said retracted positions in response to movement of said shifting means respectively through (1) an elevation stroke and (2) a retraction stroke;     triggering means for moving said shifting means through initial portions of said elevation and retraction strokes in respective response to movement of said lid portion toward said open and closed positions thereof; and   final drive means for moving said shifting means through final portions of said elevation and retraction strokes in respective response to movement of said shifting means by said triggering means through said initial portions of said elevation and retraction strokes.   
     
     
       23. The portable computer of claim 22 wherein said portable computer is a notebook computer. 
     
     
       24. The portable computer of claim 22 wherein said final drive means include a bistable spring structure operatively connected to said shifting means. 
     
     
       25. The portable computer of claim 22 wherein said triggering means are operative only during an initial portion of the opening movement of said lid portion, and a final portion of the closing movement of said lid portion. 
     
     
       26. The portable computer of claim 25 wherein said final drive means include a bistable spring structure operatively connected to said shifting means. 
     
     
       27. A portable computer comprising: a base housing;   a lid housing mounted on said base housing for pivotal movement relative thereto between open and closed positions;   a collapsible keyboard carried by said base housing and including: a plurality of keys supported for movement between elevated and retracted positions, and   a shifting structure operative to (1) shift said keys from said retracted positions to said elevated positions and (2) shift said keys from said elevated positions to said retracted positions in respective response to movement of said shifting structure through elevation and retraction strokes;     a linkage structure drivingly connected to said shifting structure and being engageable by said lid portion during an initial portion of its opening movement to drive said shifting structure through an initial portion of said elevation stroke, and engageable by said lid portion during a final portion of its closing movement to drive said shifting structure through an initial portion of said retraction stroke; and   a bistable spring structure drivingly connected to said shifting structure for moving said shifting structure through final portions of said elevation and retraction strokes, and then releasably and resiliently retaining said shifting structure in the resulting stroke end position thereof, in respective response to movement of said shifting structure through said initial portions of said elevation and retraction strokes.   
     
     
       28. The portable computer of claim 27 wherein said portable computer is a notebook computer. 
     
     
       29. The portable computer of claim 27 wherein said shifting structure includes a sheet member having mounted on a side thereof a mutually spaced series of resilient key return spring members, and said linkage structure and said bistable spring structure are connected to said sheet member. 
     
     
       30. The portable computer of claim 29 wherein said resilient key return spring members are elastomeric dome members. 
     
     
       31. The portable computer of claim 27 wherein said elevation and retraction strokes are oppositely directed. 
     
     
       32. The portable computer of claim 31 wherein said base housing has a front side, and said elevation stroke is forwardly directed. 
     
     
       33. The portable computer of claim 31 wherein said base housing has a front side, and said elevation stroke is rearwardly directed. 
     
     
       34. The portable computer of claim 27 wherein said linkage structure is engaged by said lid housing only during said initial portion of said opening movement of said lid housing and said final portion of said closing movement of said lid housing. 
     
     
       35. The portable computer of claim 27 wherein said linkage structure includes: a striker member carried by said lid housing,   a pivotally supported lever member having first and second differently sloped ramp surfaces respectively engageable by said striker member as said lid housing is being opened and closed to cause pivotal movement of said lever member in opposite directions, and   a drive member interconnected between said shifting structure and said lever member and being translatable in response to rotation of said lever member.   
     
     
       36. The portable computer of claim 27 wherein said bistable spring structure includes a body portion supported for rotation relative to said shifting structure and drivingly connected thereto, and a spring portion engaging said body portion in a manner permitting said body portion to rotate between two stable positions through an intermediate unstable position. 
     
     
       37. The portable computer of claim 36 wherein: said shifting structure has a slot therein,   said body portion has a drive pin received in said slot, and   said spring portion exerts generally oppositely directed forces on said body portion in directions generally transverse to its rotational axis.   
     
     
       38. The portable computer of claim 27 wherein: said shifting structure has spaced pairs of oppositely ramped drive surfaces, and   said bistable spring structure includes a pair of spring members supported adjacent said spaced pairs of oppositely ramped drive surfaces and having generally V-shaped end portions resiliently engaging said drive surfaces.   
     
     
       39. The portable computer of claim 27 wherein: said shifting structure has spaced pairs of oppositely ramped drive surfaces, and   said bistable spring structure includes a generally U-shaped spring member having generally V-shaped free end portions resiliently engaging said drive surfaces.   
     
     
       40. The portable computer of claim 27 wherein: said shifting structure has spaced pairs of oppositely ramped drive surfaces, and   said bistable spring structure includes a generally rectangular spring member having opposite side portions with generally V-shaped protrusions formed thereon and resiliently engaging said drive surfaces.   
     
     
       41. The portable computer of claim 40 wherein said protrusions are inwardly directed protrusions. 
     
     
       42. The portable computer of claim 40 wherein said protrusions are outwardly directed protrusions. 
     
     
       43. The portable computer of claim 27 wherein said bistable spring structure includes a pair of telescoped, axially spring-biased tie rod assemblies each having a first end pivotally connected to said shifting structure, and a second end pivotally supported external to said shifting structure.